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Preview of Drop CSV Viewer

Drop CSV Viewer by soyasis

Drag a CSV file onto any page to open it as a clean table in a new tab. Filter, sort, resize and export. 100% local and open source.

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Extension Metadata

Screenshots
Dark mode view: select a column, row, or range of cells to see instant stats: Sum, Average, Min, Max, Count, and Unique.Light mode view: select a column, row, or range of cells to see instant stats: Sum, Average, Min, Max, Count, and Unique.
About this extension
Read local CSV and TSV files without links or a spreadsheet app.

Just drop it in
Drag a .csv or .tsv onto any open Firefox tab and it opens as a clean table in a new tab. No URL, no upload, no "open file" dialog, no Excel.

Features
- Type to filter across all columns
- Click the ▼ next to a column to sort (numbers sort as numbers)
- See live Sum, Average, Min, Max, Count and Unique
- Copy any selection with ⌘/Ctrl-C to paste straight into Sheets or Excel
- Drag a column's right edge to resize; sticky header and first column
- Download the current view (filter + sort applied) back to CSV

Private by design
- 100% local: no network requests, no analytics, no data collection
- Open source (MIT) — read every line on GitHub
- Light & dark, follows your system theme (or toggle it)
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Permissions and data

Required permissions:

  • Access browser tabs
  • Access browser activity during navigation
  • Access your data for all websites

Data collection:

  • The developer says this extension doesn't require data collection.
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More information
Add-on Links
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Version
1.4.0
Size
21.8 KB
Last updated
4 days ago (Jun 21, 2026)
Related Categories
  • Web Development
License
MIT License
Version History
  • See all versions
Tags
  • dark mode
  • privacy
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